This application claims the priority of Korean Patent Application No. 2003-0025561, filed on Apr. 22, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
(a) Field of the Invention
The present invention relates to an electrophoretic display device.
(b) Description of the Related Art
An electrophoretic display device (EPD) is one of flat panel display devices that are used for electronic books. The EPD includes two panels including field-generating electrodes and a plurality of micro-capsules interposed between the panels. Each micro-capsule includes electric ink containing a plurality of white and black pigment particles that are negatively and positively charged respectively. Upon application of an electric field in the micro-capsules, the black and white particles move in opposite directions to display images.
The electrophoretic display is described in detail in the U.S. Pat. No. 6,017,584 entitled “Multi-color electrophoretic displays and materials for making the same”, issued Jan. 25, 2000 and assigned to E-ink corporation, which is hereby incorporated by reference in its entirety.
The EPD has high reflectance and contrast regardless of viewing directions and thus it is comfortable for a viewer to see a screen of the EPD as if he sees a paper. Since the micro-capsule has bistability of black and white states, it maintains the shape without a constant supply of voltages across the micro-capsule, once set for black or white. Accordingly, the EPD requires less power consumption. In addition, the EPD does not require polarizers, alignment layers, liquid crystal, etc., that are expensive components for a liquid crystal display, which reduces the manufacturing costs.
However, since the conventional EPD does not have a black matrix for covering the areas that are not controlled by the field-generating electrodes, the light leaks between pixels and current due to the photocurrent generated by incident lights coming from outside.